Moisture separators are provided for gas turbines for marine applications as the moisture particles in the air generally contain salt which, if they should be introduced into the turbine, would deleteriously affect the component parts of the turbine, as for example, by chemical corrosion. Further, the dry particles entrained in the air, for example, sand and/or salt crystals, can cause "pitting" of the turbine components if they are not removed. However, by far the greatest concern is the moisture particles containing salt.
Although various types of separator assemblies have been proposed for use in marine applications to minimize the passage of air containing such particles to the turbine, it will also be understood that of an even greater importance is the provision of a substantial air flow being maintained to the turbine. In fact, this is of such importance that it is deemed imperative that air always be delivered to the turbine, even if it means delivering air which might otherwise damage the turbine components, i.e., air having moisture and/or salt therein.
Accordingly, in the past, doors or passageways, known as "Blow in" doors, have been provided in the air ducts adjacent to the moisture separators which are automatically opened if the pressure drop across the moisture separator increases too much, i.e., beyond a predetermined limit which might otherwise result in the turbine being starved of air flow. In accordance with these prior art arrangements, unfiltered air is thus allowed to flow into the air duct, bypassing the moisture separator, to be delivered to the turbine.
Such an increase in the pressure drop across the moisture separator can result from freezing or icing up of the moisture separators when the ships on which they are mounted are in cold or icy waters since the moisture separators for the gas turbines on such ships are generally located high up on the ship where they are unprotected from the elements. For example, the moisture that is removed from the air by the moisture separator can freeze in the moisture separator, thereby significantly blocking the flow of air through the separator which, in turn, causes the pressure drop across the moisture separator to increase, and a consequent decrease in the amount of air being delivered to the turbine.
Our U.S. Pat. No. 4,312,645 describes a simplified separator assembly for an air intake duct of a turbine device for normally removing particulate matter entrained in air being introduced into the turbine device, the air being introduced to flow through the air duct in a first direction. The separator assembly comprises separating means for removing particulate matter entrained in air passing therethrough; frame means for supporting the separating means; pivotal mounting means for pivotably mounting the frame means in the air duct so as to pivot about an axis extending in a second direction which is transverse to the first direction, and so that the frame means when mounted in the air duct is pivotably movable between a first position in which the separating means, and a second position in which the air duct bypasses the separating means; sensing means for sensing the pressure differential of the air across the separating means; and clamping means for normally clamping the frame means in the first position when the frame means is mounted in the air duct, said clamping means being operatively connected to the sensing means so that the clamping means is responsive to the sensing means sensing a pressure differential greater than a predetermined pressure difference to release the frame means from the first position so that the air flowing into the air duct causes the frame means to pivot about the axis toward the second position. In this way, air flow will be maintained to the turbine device. Thus, in the separator assembly of that U.S. patent, the separating means is opened in the direction of air flow by the pressure of the air.
It is an object of the present invention to provide other forms of separator assembly which allow air to bypass the separating means when necessary.